For those interested in the entheogenic San Pedro (Huachuma) or Peyote cacti, this is an interesting article on the near-mythical Cactus of the Four Winds.
It is very possible that humans have caused some ancient, powerful psychoactive plants to go extinct. Soma is the most notable one of these. It may be that some of these plants were/are very rare, and we simply loved them to death. It will be interesting to see if this one (if truly a separate plant) can be found still living in some strange nook of the Peruvian mountains or deserts.